Summary
Impact: Remote Code Execution. Microsoft rating: Critical. Not known to be exploited — Exploitation More Likely. Customer action: Required.
Details
How could an attacker exploit the vulnerability?
In a network-based attack, an authenticated attacker, as at least a Site Owner, could write arbitrary code to inject and execute code remotely on the SharePoint Server.
There are multiple update packages available for some of the affected software. Do I need to install all the updates listed in the Security Updates table for the software?
Yes. Customers should apply all updates offered for the software installed on their systems. If multiple updates apply, they can be installed in any order.
Security updates
16.0.10417.20198 — https://support.microsoft.com/help/5002894
16.0.10417.20198 — https://support.microsoft.com/help/5002896
16.0.19725.20522 — https://support.microsoft.com/help/5002893
Vulnerabilities 1
-
High 8.8
Microsoft SharePoint Server Remote Code Execution Vulnerability
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Revision history
-
#1
Information published.
References
-
CVE-2026-65665 Microsoft SharePoint Server Remote Code Execution Vulnerability - HTML
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65665
-
Microsoft Exploitability Index
https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1
-
Microsoft Support Lifecycle
https://support.microsoft.com/lifecycle
-
Common Vulnerability Scoring System
https://www.first.org/cvss